Electron tube



June 30. 1931. KRUGER 1,812,489

ELECTRON TUBE June 30, 1931.

A. KRUGER 1,812,489

ELECTRQN TUBE Filed Jan. 26. 1928 2 She ets-Sheet 2 9mm M M Patented June 30, 1931 UNITED STATES PATENT OFFICE ALBERT KRT IGER, OF BERLIN, (.ErERlVIANY, ASSIGNOR TO SIEMENS-SCHUCKERTWERKE AKTIENGESELLSCHAFT, OF IBERLIN-SIEMENSSTADT, GER-MANY, A. CORPORATION OF GERMANY ELECTRON TUBE Application filed January 26, 1928, Serial No.

My invention relates to improvements in electron tubes and more specifically to leading-in means for such tubes. One object of my invention is to employ a metal ring fused at the ends to the wall of the tube or bulb, the central portion of said metal ring being of considerable greater thickness than the ends to be sealed with the material of the tube. A further object of my invention is to construct the external connecting members to the said metal ring as tubes. The leading-in device according to my invention has the advantage that the fused-in ring is capable of withstanding great mechanical strains, while the fusing of the ring to the wall of the tube can easily and reliably be effected, due to the tapering of the ends of the tube down to thin sheet metal rings, so that a perfect seal is formed.

In order that my invention may be fully understood I will now describe it with reference to the drawings affixed hereto and forming part of my specification.

In the drawings Fig. 1 represents a longitudinal section through the tubular leading-in device with the adjacent portions of the wall of the bulb and the connecting leads,

Fig. 2, a longitudinal section through another modification of the leading-in metal ring itself,

Fig. 3, a longitudinal section through a third embodiment of my invention with adjacent parts of the wall of the bulb and connecting leads, and

Fig. 4, a longitudinal section through a complete electron tube, vacuum tube or thermionic valve equipped with my improved leading-in device.

Like parts are indicated by like letters of reference throughout all the figures of the drawings.

Referring to Fig. 1 of the drawings, it will be seen that the ring to be fused into the wall of the bulb or vessel consists ofa thick-walled metal cylinder which tapers at both ends into thin-walled rings 2 and 3 which are fused to the wall of the bulb or vessel 4. For attaching the connecting leads the ring is on the inside shrunk upon the inner metal tube 5 249,579, and in Germany January 31, 1927.

and an outer metal tube 6 is shrunk on to the ring.

As Fig. 4 clearly shows the two metal tubes 5 and 6 serve as one of the external connecting leads to the incandescent cathode 8 of a thermionic valve having the anode 7. The second lead of the incandescent cathode is formed by a rod 10 surrounded by the tubes 5 and 6.

Fig. 2 of the drawings illustrates a similar construction of the fused-in and sealed ring. The tapering of the ends of the ring has, however, been carried out in a slightly different manner.

In the embodiment of my invention illustrated in Fig. 3 the connecting leads 5 and 6 are attached to the ring 1 by a screw connection. The ring 1 is here provided with in ternal and external threading along its central portion. This is easily possible in view of the thickening of the ring at its central portion.

Various modifications and changes may be made without departing from the spirit and the scope of the invention, and I desire, therefore, that only such limitations shall be placed thereon as are imposed by the prior art.

I claim as my invention In an electron tube, a leadingin device through the wall of the tube consisting of a metal ring fused to portions of the wall of the tube at both ends to form a portion of the wall, said ring being considerably thicker in its central portion than at the ends for sealing the ring to the wall of the tube, and

an internal and an external tubular conductor threaded to the enlarged central portion of said metal ring.

In testimony whereof I afliX my signature.

ALBERT KRIIGER. 

